PT - JOURNAL ARTICLE AU - Meyerzon, Marina AU - Fridolfsson, Heidi N. AU - Ly, Nina AU - McNally, Francis J. AU - Starr, Daniel A. TI - UNC-83 is a nuclear-specific cargo adaptor for kinesin-1-mediated nuclear migration AID - 10.1242/dev.038596 DP - 2009 Aug 15 TA - Development PG - 2725--2733 VI - 136 IP - 16 4099 - http://dev.biologists.org/content/136/16/2725.short 4100 - http://dev.biologists.org/content/136/16/2725.full SO - Development2009 Aug 15; 136 AB - Intracellular nuclear migration is essential for many cellular events including fertilization, establishment of polarity, division and differentiation. How nuclei migrate is not understood at the molecular level. The C. elegans KASH protein UNC-83 is required for nuclear migration and localizes to the outer nuclear membrane. UNC-83 interacts with the inner nuclear membrane SUN protein UNC-84 and is proposed to connect the cytoskeleton to the nuclear lamina. Here, we show that UNC-83 also interacts with the kinesin-1 light chain KLC-2, as identified in a yeast two-hybrid screen and confirmed by in vitro assays. UNC-83 interacts with and recruits KLC-2 to the nuclear envelope in a heterologous tissue culture system. Additionally, analysis of mutant phenotypes demonstrated that both KLC-2 and the kinesin-1 heavy chain UNC-116 are required for nuclear migration. Finally, the requirement for UNC-83 in nuclear migration could be partially bypassed by expressing a synthetic outer nuclear membrane KLC-2::KASH fusion protein. Our data support a model in which UNC-83 plays a central role in nuclear migration by acting to bridge the nuclear envelope and as a kinesin-1 cargo-specific adaptor so that motor-generated forces specifically move the nucleus as a single unit.